Fatty acid amides represent a family of bioactive lipids with diverse cellular and physiological effects. Fatty acid amides are hydrolyzed to their corresponding fatty acids by an enzyme known as fatty acid amide hydrolase (FAAH). FAAH is a mammalian integral membrane serine hydrolase responsible for the hydrolysis of a number of primary and secondary fatty acid amides, including the neuromodulatory compounds anandamide and oleamide. Anandamide (arachidonoyl ethanolamide) has been shown to possess cannabinoid-like analgesic properties and is released by stimulated neurons. The effects and endogenous levels of anandamide increase with pain stimulation, implying its role in suppressing pain neurotransmission and behavioral analgesia. Supporting this, FAAH inhibitors that elevate brain anandamide levels have demonstrated efficacy in animal models of pain, inflammation, anxiety, and depression. Lichtman, A. H. et al. (2004), J. Pharmacol. Exp. Ther. 311, 441-448; Jayamanne, A. et al. (2006), Br. J. Pharmacol. 147, 281-288; Kathuria, S. et al. (2003), Nature Med., 9, 76-81; Piomelli D. et al. (2005), Proc. Natl. Acad. Sci. 102, 18620-18625.
The compounds of the present invention are inhibitors of FAAH and therefore are useful in the treatment of a wide range of disorders, particularly pain. Other conditions that may be treated with the compounds of the present invention urinary incontinence, overactive bladder, emesis, cognitive disorders, anxiety, depression, sleeping disorders, eating disorders, movement disorders, glaucoma, psoriasis, multiple sclerosis, cerebrovascular disorders, brain injury, gastrointestinal disorders, hypertension, or cardiovascular disease.